Darth Fader: Using wavelets to obtain accurate redshifts of spectra at very low signal-to-noise

We present the DARTH FADER algorithm, a new wavelet-based method for estimating redshifts of galaxy spectra in spectral surveys that is particularly adept in the very low SNR regime. We use a standard cross-correlation method to estimate the redshifts of galaxies, using a template set built using a PCA analysis on a set of simulated, noise-free spectra. Darth Fader employs wavelet filtering to both estimate the continuum & to extract prominent line features in each galaxy spectrum. A simple selection criterion based on the number of features present in the spectrum is then used to clean the catalogue: galaxies with fewer than six total features are removed as we are unlikely to obtain a reliable redshift estimate. Applying our wavelet-based cleaning algorithm to a simulated testing set, we successfully build a clean catalogue including extremely low signal-to-noise data (SNR=2.0), for which we are able to obtain a 5.1% catastrophic failure rate in the redshift estimates (compared with 34.5% prior to cleaning). We also show that for a catalogue with uniformly mixed SNRs between 1.0 & 20.0, with realistic pixel-dependent noise, it is possible to obtain redshifts with a catastrophic failure rate of 3.3% after cleaning (as compared to 22.7% before cleaning). Whilst we do not test this algorithm exhaustively on real data, we present a proof of concept of the applicability of this method to real data, showing that the wavelet filtering techniques perform well when applied to some typical spectra from the SDSS archive. The Darth Fader algorithm provides a robust method for extracting spectral features from very noisy spectra. The resulting clean catalogue gives an extremely low rate of catastrophic failures, even when the spectra have a very low SNR. For very large sky surveys, this technique may offer a significant boost in the number of faint galaxies with accurately determined redshifts.Comment: 22 pages, 15 figures. Accepted for publication in Astronomy & Astrophysic

Exploring the contribution of efflux on the resistance to fluoroquinolones in clinical isolates of Staphylococcus aureus

<p>Abstract</p> <p>Background</p> <p>Antimicrobial resistance mediated by efflux systems is still poorly characterized in <it>Staphylococcus aureus</it>, despite the description of several efflux pumps (EPs) for this bacterium. In this work we used several methodologies to characterize the efflux activity of 52 <it>S. aureus </it>isolates resistant to ciprofloxacin collected in a hospital in Lisbon, Portugal, in order to understand the role played by these systems in the resistance to fluoroquinolones.</p> <p>Results</p> <p>Augmented efflux activity was detected in 12 out of 52 isolates and correlated with increased resistance to fluoroquinolones. Addition of efflux inhibitors did not result in the full reversion of the fluoroquinolone resistance phenotype, yet it implied a significant decrease in the resistance levels, regardless of the type(s) of mutation(s) found in the quinolone-resistance determining region of <it>grlA </it>and <it>gyrA </it>genes, which accounted for the remaining resistance that was not efflux-mediated. Expression analysis of the genes coding for the main efflux pumps revealed increased expression only in the presence of inducing agents. Moreover, it showed that not only different substrates can trigger expression of different EP genes, but also that the same substrate can promote a variable response, according to its concentration. We also found isolates belonging to the same clonal type that showed different responses towards drug exposure, thus evidencing that highly related clinical isolates may diverge in the efflux-mediated response to noxious agents. The data gathered by real-time fluorometric and RT-qPCR assays suggest that <it>S. aureus </it>clinical isolates may be primed to efflux antimicrobial compounds.</p> <p>Conclusions</p> <p>The results obtained in this work do not exclude the importance of mutations in resistance to fluoroquinolones in <it>S. aureus</it>, yet they underline the contribution of efflux systems for the emergence of high-level resistance. All together, the results presented in this study show the potential role played by efflux systems in the development of resistance to fluoroquinolones in clinical isolates of <it>S. aureus</it>.</p

Modular proteins from the Drosophila sallimus (sls) gene and their expression in muscles with different extensibility

The passive elasticity of the sarcomere in striated muscle is determined by large modular proteins, such as titin in vertebrates. In insects, the function of titin is divided between two shorter proteins, projectin and sallimus (Sls), which are the products of different genes. The Drosophila sallimus (sls) gene codes for a protein of 2 MDa. The N-terminal half of the protein is largely made up of immunoglobulin domains and unique sequence; the C-terminal half has two stretches of sequence similar to the elastic PEVK region of titin, and at the end of the molecule there is a region of tandem Ig and fibronectin domains. We have investigated splicing pathways of the sls gene and identified isoforms expressed in different muscle types, and at different stages of Drosophila development. The 5’ half of sls codes for zormin and kettin; both proteins contain Ig domains and can be expressed as separate isoforms, or as larger proteins linked to sequence downstream. There are multiple splicing pathways between the kettin region of sls and sequence coding for the two PEVK regions. All the resulting protein isoforms have sequence derived from the 3’ end of the sls gene. Splicing of exons varies at different stages of development. Kettin RNA is predominant in the embryo, and longer transcripts are expressed in larva, pupa and adult. Sls isoforms in the indirect flight muscle (IFM) are zormin, kettin and Sls(700), in which sequence derived from the end of the gene is spliced to kettin RNA. Zormin is in both M-line and Z-disc. Kettin and Sls(700) extend from the Z-disc to the ends of the thick filaments, though, Sls(700) is only in the myofibril core. These shorter isoforms would contribute to the high stiffness of IFM. Other muscles in the thorax and legs have longer Sls isoforms with varying amounts of PEVK sequence; all span the I-band to the ends of the thick filaments. In muscles with longer Ibands, the proportion of PEVK sequence would determine the extensibility of the sarcomere. Alternative Sls isoforms could regulate the stiffness of the many fibre types in Droso phila muscles

2021-2022 4 Hands & 176 Keys from the Studio of Lisa Leonard with Special Guest Artists

Special Guest Artists Katherine Riley, flute/piccolo Nat Farrar, clarinet Andrew Nowak, xylophone/percussion Sebastian Orellana, violin Manuel Mendes, violin Moises Molina, violin Daniel Guevara, violin Elena Galentas, viola Gabe Galley, viola Devin LaMarr, cello Dezmond Rogers, double bas

2021-2022 New Friends Dreams and Directions

https://spiral.lynn.edu/foc-events/1038/thumbnail.jp

COMPETITIVIDADE DA CADEIA PRODUTIVA DO BIODIESEL NO ESTADO DA BAHIA: UMA ANÁLISE DOS FATORES AMBIENTAIS NA AGRICULTURA FAMILIAR

A preocupação com os problemas ambientais é inerente a todos os processos de geração de energia. Junto à estrutura de produção, as infraestruturas, em suas diversas etapas da cadeia produtiva, têm-se no biodiesel um duplo desafio de dar suporte ao mercado de energia e de responder satisfatoriamente aos impactos socioambientais, principalmente no que se refere a competição por alimentos em relação as matérias primas para a sua produção. Este trabalho tem como objetivo avaliar os fatores de competitividade com foco nas questões ambientais na cadeia produtiva do biodiesel da agricultura familiar no Estado da Bahia. Foi utilizado o referencial teórico baseado em pesquisa exploratória através de um levantamento bibliográfico e um estudo de caso no Estado da Bahia de algumas oleaginosas. Os impactos ambientais do biodiesel devem ser analisados em toda cadeia produtiva. Para as oleaginosas incluem as etapas da agricultura, beneficiamento, extração e refino do óleo, produção do biodiesel, distribuição e uso do combustível. Concluiu-se que, mesmo em uma condição não ideal de produção agrícola, o biodiesel no Brasil apresenta ganhos ambientais em relação aos combustíveis fósseis, contudo, pelo simples fato do biodiesel ser uma alternativa energética renovável, não é condição suficiente para torná-lo ambientalmente correto

Measuring the Impact of Conservation : The Growing Importance of Monitoring Fauna, Flora and Funga

Many stakeholders, from governments to civil society to businesses, lack the data they need to make informed decisions on biodiversity, jeopardising efforts to conserve, restore and sustainably manage nature. Here we review the importance of enhancing biodiversity monitoring, assess the challenges involved and identify potential solutions. Capacity for biodiversity monitoring needs to be enhanced urgently, especially in poorer, high-biodiversity countries where data gaps are disproportionately high. Modern tools and technologies, including remote sensing, bioacoustics and environmental DNA, should be used at larger scales to fill taxonomic and geographic data gaps, especially in the tropics, in marine and freshwater biomes, and for plants, fungi and invertebrates. Stakeholders need to follow best monitoring practices, adopting appropriate indicators and using counterfactual approaches to measure and attribute outcomes and impacts. Data should be made openly and freely available. Companies need to invest in collecting the data required to enhance sustainability in their operations and supply chains. With governments soon to commit to the post-2020 global biodiversity framework, the time is right to make a concerted push on monitoring. However, action at scale is needed now if we are to enhance results-based management adequately to conserve the biodiversity and ecosystem services we all depend on.This paper was made possible by funding from the Swiss Network for International Studies to the University of Lausanne (L.F. and P.J.S.) and its partners under the project: "Unblocking the flow of biodiversity data for multi-stakeholder environmental sustainability management". The research was carried out, in part, by GNG at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). PAVB was supported by the project MACRISK-PTDC/BIA-CBI/0625/2021, through the FCT-FundacAo para a Ciencia e a Tecnologia. YNB acknowledges support from the Audemars-Watkins Foundation for the CBCR's protected area monitoring work featured in this paper.info:eu-repo/semantics/publishedVersio

Measuring the Impact of Conservation: The Growing Importance of Monitoring Fauna, Flora and Funga

Many stakeholders, from governments to civil society to businesses, lack the data they need to make informed decisions on biodiversity, jeopardising efforts to conserve, restore and sustainably manage nature. Here we review the importance of enhancing biodiversity monitoring, assess the challenges involved and identify potential solutions. Capacity for biodiversity monitoring needs to be enhanced urgently, especially in poorer, high-biodiversity countries where data gaps are disproportionately high. Modern tools and technologies, including remote sensing, bioacoustics and environmental DNA, should be used at larger scales to fill taxonomic and geographic data gaps, especially in the tropics, in marine and freshwater biomes, and for plants, fungi and invertebrates. Stakeholders need to follow best monitoring practices, adopting appropriate indicators and using counterfactual approaches to measure and attribute outcomes and impacts. Data should be made openly and freely available. Companies need to invest in collecting the data required to enhance sustainability in their operations and supply chains. With governments soon to commit to the post-2020 global biodiversity framework, the time is right to make a concerted push on monitoring. However, action at scale is needed now if we are to enhance results-based management adequately to conserve the biodiversity and ecosystem services we all depend on